Crop drying systems

ABSTRACT

A large capacity crop drier has an elongated chamber which may include transparent wall and roof partitions to admit solar radiations. A feeding device which may include a doser conveys crop to be dried into the chamber where it is chopped by retractable knives and carried back and forth through the chamber on superimposed endless belts starting at the top. The lower belt discharges back into the feeding device via a one-way conveyor closing the path of the drying crop. Air which may be heated is introduced into the chamber under the lowest belt opposite the feeding device and is exhausted on the same side that it was introduced or over walls under a raised roof. When desired by movement of a rear flap which may carry a conveying belt, the drier crop is discharged from the chamber via the flap to a blower conveyor. In a modification, the chamber has a moving belt floor, a blower which displaces air to under the floor and up through the chamber, and a mechanism for stirring crop in the chamber which automatically rides back and forth on tracks provided in the chamber.

United States Patent [19] van der Lely Jan. 23, 1973 [$4] CROP DRYINGSYSTEMS [76] lnventor: Cornelis van der Lely, 7 Bruschenrain, Zug,Switzerland [22] Filed: June 19, 1970 [21] Appl. No.: 47,258

[30] Foreign Application Priority Data June 19, 1969 Netherlands..6909348 [52] US. Cl. ..34/102, 34/189, 34/207, 34/236 [51] lnt. Cl..F26b 19/00 [58] Field of Search ..34/102, 189, 190, 203, 207, 34/218;130/22 R, 22 A; 198/195; 56/14.3, 14.5

[56] References Cited UNITED STATES PATENTS 170,469 11/1875 Chapin..34/203 312,341 2/1885 Duryea... ..34/203 X 936,947 10/1909 Roth..34/203 999,706 8/1911 Eichler... 34/203 X 1,176,685 3/1916 Meakin34/203 X 1,678,711 7/1928 Shipman ..34/93 X 2,228,192 l/1941 Arthur34/203 X 2,507,756 5/1950 Boylan ..74/112 2,657,032 10/1953 Tomlinson..34/203 X 2,763,119 9/1956 Helfeld 198/10 X 3,367,038 2/1968 Bishop..34/52 X 3,446,347 5/1969 French et a1 ..130/22 R FOREIGN PATENTS ORAPPLICATIONS 631,422 11/1949 Great Britain ..198/195 PrimaryExaminer-Frederick L. Matteson Assistant Examiner-Harry B. RameyAttorney-Mason, Mason & Albright [57] ABSTRACT A large capacity cropdrier has an elongated chamber which may include transparent wall androof partitions to admit solar radiations. A feeding device which mayinclude a closer conveys crop. to be dried into the chamber where it ischopped by retractable knives and carried back and forth through thechamber on superimposed endless belts starting at the top. The lowerbelt discharges back into the feeding device via a oneway conveyorclosing the path of the drying crop. Air which may be heated isintroduced into the chamber under the lowest belt opposite the feedingdevice and is exhausted on the same side that it was introduced or overwalls under a raised roof. When desired by movement of a rear flap whichmay carry a conveying belt, the drier crop is discharged from thechamber via the flap to a blower conveyor. in a modification, thechamber has a moving belt floor, a blower which displaces air to underthe floor and up through the chamber, and a mechanism for stirring cropin the chamber which automatically rides back and forth on tracksprovided in the chamber.

22 Claims, 12 Drawing Figures PATENTEUJANZIBISB 3 711 959 SHEET 1 BF 8INVENTOR ogg PATENTEUJAHZB 1975 3,711,959

SHEET 2 0F 8 WWO W PATENTEDJAHZB I973 3,711,959

sum 6 [IF 8 INVENTOR COQA/EZAS 1/7/V DER [ELF WM W CROP DRYING SYSTEMSSUMMARY OF THE INVENTION This invention relates to crop drying systemsof the kind comprising members for conveying crop received from atransport vehicle through a drying chamber.

Known systems of the kind mentioned above do not have sufficientcapacity to enable them to hold a full load of crop from a conventionaltransport vehicle and this involves both delay in drying and increaseddrying costs. An object of the invention is to avoid or reduce thisdisadvantage of known systems.

According to one aspect of the invention, there is provided a dryingsystem of the kind set forth, wherein heating apparatus is provided toenable air which may be at a raised temperature compared with that ofthe atmosphere to be fed to crop to be dried, and wherein the conveyingmembers are constructed and arranged in such a way that a quantity ofcrop can be maintained in continuous circulation through a path whichmay be closed in the drying chamber during a drying operation.

For a better understanding of the invention, and to show how the samemay be carried into effect, reference will now be made, by way ofexample, to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectional side elevationof a crop drying system in accordance with the invention,

FIG. 2 is an enlarged view showing a crop-receiving and other regions ofthe system in greater detail,

FIG. 3 corresponds to FIG. 2 but illustrates an alternativeconstruction,

FIG. 4 corresponds to FIGS. 2 and 3 but illustrates a still furtheralternative construction,

FIG. 5 corresponds to FIG. 1 but is a diametrically opposite viewillustrating the drive transmission to endless conveyors of the system,

FIG. 6 is a plan view illustrating the crop discharge region of thesystem,

FIG. 7 is a side elevation corresponding to FIG. 6,

FIG. 8 is a section taken on the line VIIIVIII of FIG. 1,

FIG. 9 is a sectional side elevation, to an enlarged scale, illustratingthe construction of one of the endless conveyors of the system and therotary support thereof,

FIG. 10 is a side elevation corresponding to FIG. 1 but to a reducedscale illustrating an alternative form of crop drying system inaccordance with the invention,

FIG. 11 is a front elevation of the system of FIG. 10 as seen in thedirection indicated by an arrow XI in FIG. 10, and

FIG. 12 corresponds to FIG. 10 but illustrates a further alternativesystem in accordance with the invention which incorporates displaceabledischarging or dosing mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring firstly to FIGS. 1and 2 of the drawings, the drying system which is illustrated takes theform of a superstructure having an elongated rectangular ground plate 1to which substantially vertical side walls 2 are connected. The sidewalls 2 are interconnected by inclined front and rear walls 3 and 5,respectively, and

a substantially horizontal roof 4. The front wall 3 is formed with aninlet opening 6 for the crop which is to be dried, said inlet opening 6extending throughout the width of the superstructure which widthconveniently has a magnitude of 250 centimeters. A space 7 is providedbeneath the inclined rear wall 5 of the superstructure to accommodateparts of the system which supply the heating and drying gas during theuse of that system. These parts will be described below.

The inlet opening 6 communicates with a feeding channel 8 a lower curvedportion 9 of which leads to an upwardly and rearwardly inclinedsubstantially straight portion 10 whose uppermost end communicates withthe interior of a large drying chamber 1 1. It can be seen from thedrawings that a feeding conveyor 12 is provided throughout substantiallythe whole of the width of the superstructure to move received cropthrough the feeding channel 8 to the drying chamber 11. The feedingconveyor 12 includes a plurality of feeding members 15 that are spacedapart from one another laterally of the superstructure. The feedingmembers 15 are rotatably connected to the crank pins of upper and lowercrank shafts 13 which crank shafts have their crank pins offset from oneanother at intervals around the axes of rotation of the crank shafts.Successive feeding members 15 are connected to the successively offsetcrank pins of the upper and lower crank shafts 13 and each member 15carries a row of resilient tines 14 which project through gaps between aplurality of parallel strips 16 that afford the upper wall of thefeeding channel 8. The lowermost and foremost ends of the feedingmembers 15 take the form of tightly curved portions each provided with aplurality, such as five, of resilient tines 17 which extendsubstantially radially with respect to the center of curvature of thecurved portion concerned. The tines 17 also project through the gapsbetween the strips 16.

During the operation of the feeding conveyor 12, the crank shafts l3rotate in the direction indicated by the arrows A in FIG. 2 of thedrawings and it will be evident that the tines l4 and 17 are therebycaused to move through the portions 10 and 9 respectively of the feedingchannel 8 in such a direction as to move crop contained therein towardsthe end of the channel 8 that opens into the drying chamber 11. As thetines 14 and 17 pass through portions of their paths of movement thatwould tend to move the crop in an opposite direction through the channel8, they are withdrawn between the strips 16 to an extent such that theybecome substantially ineffective. When each feeding member 15 reachesits point of closest proximity to the strips 16, the tines 14 that arecarried thereby have their tips very close to, or in contact with, theperforated rear wall of the straight portion 10 of the channel 8. Thetines 17 also move very close to, or in contact with, the lower wall ofthe curved portion 9 as they project into that portion to a maximumextent. It will be noted that an opening 18 is formed in the lower wallof the feeding channel 8 at approximately the point at which the lowercurved portion thereof merges into the straight portion thereof. Thisopening 18 establishes a connection with a leading lower region of thedrying chamber 11.

The drying chamber 11 accommodates four endless conveyors I9 arrangedone above the other in relative- Iy parallel relationship. Each conveyor19 includes two chains 21 (FIG. 9) that are spaced apart from oneanother laterally of the superstructure. The upper and lower runs of thechains 21 move over rollers (not shown) supported from guides 20 carriedby the opposite side walls 2 of the superstructure. Crop-engaging beamsor catches 22 perpendicularly interconnect the two chains 21 of eachconveyor 19 at regular short intervals, each beam or catch 22 having achannelshaped cross-section with the free ends (in cross-section) of thelimbs of the channel bent over outwardly so as to be contained in aplane parallel to, but spaced from, the plane containing the base of thechannel. The chains 21 pass around toothed pinions 23 carried by stubshafts 24 connected to the side walls 2 and it can be seen from FIG. 9of the drawings that the arrangement of the beams or catches 22 is suchthat the base of each of them is radially outermost with respect to theaxes of rotation afforded by the shafts 24 so that said bases areuppermost as the beams or catches 22 move through the upper runs of thevarious conveyors 19.

The opening 18 (FIGS. 1 and 2) is located at approximately the level ofthose ends of the two lowermost conveyors 19 that are closest to theinlet opening 6. The curved lower wall of the lower portion 9 of thefeeding channel 8 terminates in an oppositely curved portion 25 whoserearmost part is inclined rearwardly and downwardly towards the groundplate 1. A drum 27 is rotatably mounted beneath the curved portion 25and is provided with a plurality of resilient tines 26 that projectthrough slots in the curved portion 25 during passage through upperparts of their paths of movement around the axis of rotation of the drum27. The drum 27 rotates in a counterclockwise direction as seen in FIGS.1 and 2 of the drawings and it will therefore be evident that the tipsof the tines 26 follow approximately the broken-line path illustrated inFIG. 2 of the drawings which path passes upwardly from the foremost endof the lowermost conveyor 19 through the center of the opening 18 andthen steeply downwards to meet the curved portion 25 at its junctionwith the lower wall of the curved portion 9 of the feeding channel 8. Itwill be realized that the resilient deflection of the tines 26 thatcauses the non-uniform shape of the path illustrated in FIG. 2 is' theresult of those tines meeting the ends of the slots through the curvedportion 25 as the drum 27 rotates.

The space 7 beneath the rear wall of the superstructure contains aburner 28 (FIG. 8) whose delivery mouth opens into a combustion chamber29 that extends horizontally transverse to the length of thesuperstructure. The combustion chamber 29 has an outlet towards the endthereof which is remote from the burner 28 and said outlet facesforwardly towards the drying chamber 11 as can be seen in FIGS. 1 and 8of the drawings. A blower 30 is mounted in the leading wall of the space7 so as to communicate with the drying chamber 11 and the burner 28 ispreferably rated between 25,000 and I00,000 kcal. per hour so that theatmospheric air in the space 7 is not heated excessively before theblower 30 passes it substantially horizontally into a lower region ofthe drying chamber 11. The burner 28 is preferably, but not essentially,operated by liquid fuel from a cylindrical tank located immediatelyabove the upper wall of the space 7. The air and combustion gases thatare introduced into the drying chamber 11 by the blower 30 can leavethat chamber by way of an outlet opening 31 formed in an upper region ofthe rear wall 5 of the superstructure.

Crop dried in the chamber 11 can be discharged therefrom by moving overa flap 32 (FIG. 1) that is tumable about a horizontal shaft 33 extendingperpendicular to the side walls 2 between the operative positionillustrates in full lines in FIG. 1 and an inoperative position that isshown in broken lines in the same Figure. The flap 32 extends throughoutsubstantially the whole of the width of the superstructure and itslowermost edge communicates with a funnel-shaped chute 35 that isintended to co-operate, during crop discharge, with a funnel-shapedinlet 36 (FIGS. 6 and 7) of a blower-conveyor 37 that is positionedbehind the system with its delivery duct 38 leading to a neighboringcrop store, treatment apparatus or other transport mechanism (notshown).

If desired, the tines 17 (FIG. 2) at the foot of the feeding conveyor 12may be arranged so that some of them project repeatedly from the inletopening 6 in such a way as to drag crop presented to that opening intothe lower curved portion 9 of the feeding channel 8. This enables wetcrop to be unloaded from a wagon, trailer or other transport vehiclewithout the aid of any auxiliary mechanical apparatus. FIG. 3 of thedrawings illustrates an alternative construction of the feeding conveyor12 in which knife-edged teeth 17A project forwardly from the feedingmembers 15 through the gaps between the strips 16. An inlet opening 6Aof larger size than the previously described inlet opening 6 is providedand it can be seen from FIG. 3 of the drawings how the conveyor floor ofa wagon or trailer can co-operate with the system to move a load of croprearwardly into the inlet opening 6A in which opening knife-edged teeth17A perform repeated downward movements in the same manner as the tinesl4 perform repeated upward movements in the portion 10 of the feedingchannel 8. The knife-edged teeth 17A afford a dosing mechanism for theintroduction of wet or damp crop into the feeding channel 8. A largepivotally mounted flap 58A is provided in the construction illustratedin FIG. 3 of the drawings and it will be evident from that Figure thatsaid flap can be turned downwardly from the illustrated raised positionto a position in which it closes the inlet opening 6A. At least onehelical compression spring is provided to assist in raising the flap 58Afrom its closed position to its illustrated open position.

FIG. 4 of the drawings illustrates a further alternative arrangement inwhich a pair of co-operating rollers 14A are arranged at the mouth ofthe inlet opening 6 so that crop to be introduced into the feedingchannel 8 must pass between the two rollers 14A. This construction isparticularly useful when the crop to be dealt with is advantageouslycrushed before drying to effect the release of sap or other moisture,and the two rollers 14A once again afford a dosing mechanism forintroducing crop into the lower curved portion 9 of the feeding channel8, the dosing mechanism operating with a crushing action. A flapcorresponding to the flap 58A of FIG. 3 is not employed in theconstruction shown in FIG. 4.

FIGS. and 11 of the drawings illustrate an alternative form of dryingsystem in accordance with the invention which drying system, althoughbasically similar to the system that has already been described, has adrying chamber 59 of greater length than the drying chamber 11. Thesuperstructure has a roof 60 that is spaced above the upper edges of thewalls thereof by a plurality of supports 61. The roof 60 overlaps thewalls of the superstructure to some extent and is preferably formed froma heat and/or light permeable material so that solar heat may assist inthe drying operation. The roof 60 may, as illustrated, be of acorrugated formation. Due to the space between the uppermost edges ofthe walls of the superstructure and the roof 60, drying air andcombustion gases can escape from beneath the roof 60 so that an outletopening corresponding to the opening 31 is not required. There are fourrelatively parallel and vertically spaced apart superimposed endlessconveyors 62 which conveyors may be identical in construction to that ofthe conveyors 19, this construction being shown in detail in FIG. 9 ofthe drawings. However, in this case, the endless conveyors 62 aresubstantially horizontally disposed in contrast to the conveyors 19which are gently inclined to the horizontal. The lowermost conveyor 62is located immediately above a floor plate 63 of the superstructure andcrop to be dried is fed into the chamber 59 in any one of the ways thathave previously been described with reference to FIGS. 1 to 9 of thedrawings. Accordingly, the construction shown in FIG. 1 is also shown inFIGS. 10 and 11 and the same reference numerals are employed as appearin FIG. 1.

The chamber 59 has a rear wall 64 which is provided, immediately abovethe conveyor 62 that is beneath the uppermost conveyor, with an inclinedguide 65 arranged to direct the crop from the uppermost conveyor 62without difficulty onto the underlying conveyor. A blower 66 is arrangedat one side of a rear region of the superstructure (see FIG. 11) andthis blower has an outlet channel 67 that extends horizontallyperpendicular to the length of the superstructure to communicate withthe interior of the chamber 59 by way ofa duct or channel portion 68.The duct 68 communicates with an upwardly directed delivery duct 69 inwhich a closing flap 70 (FIG. 11) is pivotally mounted adjacent itslower end. The duct or channel portion 68 that is located inside thedrying system is provided with a cylindrically curved closing flap 71which also carries the support of a short endless conveyor 72. As can beseen in FIG. 10 of the drawings, the flap 71 and conveyor 72 can beturned about an axis corresponding with the longitudinal axis of theduct or channel portion 68 between two positions which are shown in fulland broken lines respectively in regard to the conveyor 72. In thebroken line position, the air supplied by the blower 66 is blown into alower region of the drying chamber 59 whereas, when the full lineposition of the conveyor 72 is employed and the closing flap 70 isopened, the conveyor 72 delivers crop into the duct or channel portion68 of the outlet channel 67 and the blower 66 operates as a blowerconveyor to feed the crop into the delivery duct 69 which ductcorresponds to the previously described duct 38 (FIGS. 6 and 7). Theconveyor 72 receives crop from the third (counting from top to bottom)of the endless conveyors 62 and it will be apparent that the blower 66can be used both for drying and subsequent delivery purposes.

The complete load of a fully loaded wagon, trailer, lorry or othercrop-transport vehicle of conventional size can be accommodated in thedrying chamber 59 at one time and this is, of course, also true of thedrying chamber 11 in the previously described embodiment. The completeload of crop can accordingly be circulated through the system for dryingpurposes for as long a period of time as is required. No burner or otherheating apparatus is employed in the system shown in FIGS. 10 and 11 ofthe drawings but it will be realized that, if required, a burner orother heater could readily be introduced to raise the temperature of thedrying air fed to the chamber 59 by the blower 66. A liquid-fuelledburner similar to the burner 28 that has already been described could beintroduced into the system of FIGS. 10 and 11 of the drawings with butlittle modification. As previously mentioned, solar heat permeates theroof 60 to assist in the drying operation when the weather is favorable.A pivotally mounted flap 58 is provided to close the inlet opening 6during continuous drying operations in both the system of FIG. 1 and thesystem of FIG. 10 of the drawings.

Inspection blinds 39 (FIGS. 1 and 5) are provided in the side walls 2 ofthe superstructure of the drying system of FIGS. 1 to 9 of the drawingsso that the drive transmission to the conveyors 19 can be inspected whenrequired. Upper portions of the side walls 2 located above the level ofthe space 7 and the blinds 39 are preferably formed from a material thatis permeable to heat and light. This material may be glass or atransparent synthetic plastics material and the side walls 2 are formedfrom sections 40 of this material which sections are in line withcorresponding sections of the roof 4 that are formed from the samematerial. An electric motor 41 drives the blower 30 and also theimpeller of the burner 28. The conveyors 19 are driven from a separateelectric motor 42 (FIGS. 5 and 8) through the intermediary of a drivingshaft 43 that extends horizontally between the side walls 2 in adirection perpendicular to the planes of those side walls. A disc 45carrying an eccentric pin is secured to one end of the driving shaft 43and a connecting rod 46 links the eccentric pin with a pawl 47 (FIG. 5)carried by one of the stub shafts 24 at the leading end of the lowermostconveyor 19. A pulley 48 is also secured to this stub shaft 24 and thispulley drives an endless V- belt, band, rope or the like 49 that passesaround pulleys 51 secured to stub shafts 24 at the leading ends of theother three conveyors l9 and also around two guide pulleys 50 rotatablyconnected to one of the side walls 2.

The pawl 47 is arranged to drive a ratchet wheel carried by the stubshaft 24 to which said pawl is rotatably connected and the amplitude ofthe oscillation of the pawl 47 which is produced in response to themovement of the connecting rod 46 can be adjusted by means of a lever 52which is linked to said pawl 47 by a control cable 53. The connectingrod 46 drives the pawl 47 through the intermediary of a spring and thelever 52 can be moved as required between a position in which all of themovement of the connecting rod 46 is utilized and a position in whichall of that movement is lost and has no driving effect upon the pawl 47.Intermediate positions of the lever 52 correspond to faster or slowerdriving speeds for the conveyors 19.

The width of the inlet opening 6 of the system substantially correspondsto the conventional width of wagons, trailers, lorries and othervehicles that are used for the collection and/or transport of crop andsuch a vehicle can discharge the whole of its load progressively intothe inlet opening 6. The rotation of the crank shafts 13 in thedirection A causes the tines l4 and 17 of the feeding members 15 to movethe received crop upwardly along the lower and rear walls of the twofeeding channel portions 9 and into the drying chamber 11. The tines 26of the drum 27 prevent crop from passing through the opening 18 into alower region of the drying chamber 11. In addition to the tines 14, eachfeeding member carries at least one knife 55 and these knives 55co-operate with a row of knives 57 carried by a support 56 that can bepivoted inwardly of the drying chamber 11 to the position shown inbroken lines in FIG. 2 of the drawings. When, as will often be the case,the collected crop is long-stalked crop, the co-operating knives 55 and57 cut this crop into smaller pieces before it reaches the dryingchamber 11 so that a more uniform distribution thereof on the conveyors19 results.

The air that is introduced into the chamber 11 by the blower has beenslightly heated by the burner 28 and some of it passes through theopening 18 and other perforations into the feeding channel 8 so that acertain amount of drying takes place even before the crop is firstintroduced into the chamber 11. Once crop has reached the top of thefeeding channel 8, it drops a short distance onto the leading end of theupper run of the uppermost conveyor 19, the crop then being slowlytransported to and fro along the successive conveyors in the directionsindicated by the arrows B in FIG. 1 of the drawings. The drying air andcombustion gases pass over and through the crop during this movement sothat an intimate drying contact therebetween is obtained. The flap 32will occupy the position thereof that is shown in broken lines in FIG. 1of the drawings during the drying operation so that the delivery chuteremains ineffective. It will be realized that, once crop has fallen ontothe lowermost conveyor 19, it will be moved therealong in the directionB until it comes close to the opening 18 at which point it is engaged bythe tines 26 and pushed through that opening. The tines 14 then elevatethe crop again through the straight portion 10 of the feeding channel 8for recirculation through the system. A quantity of crop within thesystem can, in this way, be kept in motion under the action of dryingair and combustion gases for as long a period as is desired. The systemis sufficiently large to deal with the whole load from a fully loadedwagon, trailer, lorry or other crop transport vehicle of conventionalsize and the system can be left operating for as long as is required tocomplete the drying of such a load. When the crop has been sufficientlychopped up, the support 56 and its knives 57 can be moved to the brokenline position thereof that is shown in FIG. 2 of the drawings to preventany further appreciable chopping action. The fuel consumption need notbe great despite the long period of drying time which is possiblebecause the burner 28 produces only gently heated drying air and it is,of course, possible to extinguish the burner 28 and rely upon thenatural drying action of unsaturated atmospheric air during all, orpart, of the drying of a load of crop. The flap 58 is maintained closedduring a prolonged drying operation and it will be apparent that such anoperation can continue without hindrance even during heavy rain. It isnot vital that the crop should be discharged from the system at anyparticular instant because the use of low temperature drying gasprevents overheating, scorching and the like.

A drying operation can be carried out twice a day and it is, forexample, possible to supply a wagon or trailer load of crop to thesystem in the morning and to dry that load continuously until theafternoon. The crop can then be discharged and replaced by a furthercomplete load from a wagon, trailer, truck, lorry or other vehicle.Dosing mechanism other than that previously described may be employed inintroducing crop from a transport vehicle into the inlet opening of thesystem. A drying operation can, if required, continue for a period aslong as 24 hours. The operator of the system can load the drying chamberonce a day in the knowledge that the crop will be discharged 24 hourslater in a completely dry condition irrespective of the prevailingweather conditions and without incurring very much trouble or cost. Cropis discharged from the chamber 11 by moving the flap 32 into theposition shown in full lines in FIG. 1 of the drawings so that cropwhich reaches the rear end of the uppermost conveyor 19 is deflectedover the flap 32 into the chute 35 and thence to the inlet 36 of theblower conveyor 37 (FIGS. 6 and 7). In the previously described firsttransmission from the electric motor 42 to the endless conveyors 19, afirst speed-reduction assembly 44 (FIGS. 5 and 8) is rotatably connectedto one of the side walls 2 of the superstructure and comprisesinterconnected pulleys of dissimilar sizes co-operating with V-belts,bands, ropes or the like. A pulley or sprocket wheel is secured to theend of the driving shaft 43 remote from the disc 45 that carries theeccentric pin and a V-belt, band, rope or the like or, alternatively, atransmission chain, transmits drive from this pulley or sprocket wheelto a larger pulley or sprocket wheel forming part of a secondspeedreduction assembly 54 (FIG. 5). It will be evident from FIGS. 1 and5 of the drawings that the assembly 54 rotates the drum 27 and alsotransmits rotation, at a reduced speed, to the lower one of the twocrank shafts 13 of the feeding conveyor 12. The transmission parts whichhave just been described are illustrated only in outline in thedrawings.

FIG. 12 of the drawings illustrates a drying system in which a dryingchamber 73 can again receive a full load of crop from a fully loadedwagon, pick-up trailer, truck, lorry or other crop-transport vehicle.The chamber 73 has two substantially vertical side walls 74,

a pivotally mounted front wall 75, a fixed roof 76 and a fixed rear wall77. As can be seen in FIG. 12 of the drawings, the front wall ispivotally mounted in such a way that it can be turned downwardly intothe position shown in broken lines in that figure in which it affords aramp leading upwardly from ground level to a floor 78 of the chamber 73.The floor 78 is afforded by the upper run of an endless conveyor of openconstruction that is movable over a fixed horizontal floor plate formedwith a large number of air holes. It will be realized that a wagon,trailer or other vehicle can discharge its load of crop into the space73 by moving rearwardly up the ramp afforded by the front wall 75 andemptying its crop directly onto the leading region of the endlessconveyor of the floor 78. The upper run of the conveyor of that floor isthen moved rearwardly until all of the load of crop is housed within thechamber 73. A space 79 is formed beneath the floor 78 and this space isfed with air, during operation of the system, by a blower 80 located atthe rear end of the system. The blower 80 may be associated with aburner or other heating apparatus which may be similar to the burner 28that has previously been described.

The chamber 73 accommodates a displaceable discharging or dosingmechanism 81 that is movable lengthwise through the chamber 73. Themechanism 81 includes a substantially vertical supporting structure 82carrying four vertically spaced apart drums 84 that are rotatable aboutsubstantially coplanar horizontal axes extending perpendicular to thelength of the chamber 73. Each drum 84 carries a plurality of teeth 83at 90 intervals around its axis of rotation and, as can be seen in FIG.12 of the drawings, the teeth 83 of each drum 84 are offset throughapproximately 45 with respect to those of the or each neighboring drum84. The mechanism 81 is displaceable along rails 85 secured to the sidewalls 74 with the aid of small rollers 81A that co-operate with saidrails. An electric motor (not shown) is provided for rotating the drums84 and moving the mechanism 81 lengthwise along the rails 85 and anelectrical or mechanical mechanism of known construction is preferablyprovided at the opposite ends of the chamber 73 to reverse automaticallythe direction of movement of the mechanism 81 along the rails 85.

When the chamber 73 is filled in the manner previously described, themechanism 81 will be positioned alongside the rear wall 77 of saidchamber. Subsequent to loading, the front wall 75 is placed in theposition shown in full lines in FIG. 12 of the drawings and the blower80 is operated to supply heated or unheated air to the interior of thechamber 73 through the apertured floor 78. Upper outlets (not shown) areprovided for exhausting the heated air and any combustion gases thatthere may be to the atmosphere. The mechanism 81 is caused to moveslowly to and fro through the chamber 73 during the supply of drying airand its drums 84 rotate so that their teeth 83 displace the crop betweenthem with a combing and/or chopping action dependent upon the preciseformation of the teeth 83. When the crop is fully dried, the mechanism81 can be positioned at the left-hand end of the chamber 73 as shown inFIG. 12 of the drawings and its drums 84 can be rotated to discharge thecrop slowly to a waiting conveyor, transport vehicle or the like. Theendless conveyor of the floor 78 is operated to ensure that all the cropwithin the chamber 73 is fed to the mechanism 81 and it will be realizedthat said mechanism thus acts as a discharging or dosing mechanism. Thesystem of FIG. 12 can thus be regarded either as a drying systemincorporating a discharging or dosing mechanism or as a discharging ordosing mechanism which incorporates a drying system.

The conveying members of the drying systems that have been describedwith reference to FIGS. 1 to 11 of the drawings are such that the cropwhich they carry is subject to contact with drying air throughoutsubstantially the whole of the length of each conveying member. Thetotal length of the drying path should be as long as possible and it ispreferred that this length should have a value of from 10 to meters.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

l. A device for drying crop including cut grass or the like whichcomprises:

a drying chamber which has a first space and second space which includesan internal opening for the passage of crop from said first space tosaid second space;

drying means associated with said second space of said chamber, saiddrying means including a heating mechanism for producing heated air insaid chamber and a blower means for introducing air into said secondspace;

a first conveying means mounted in said second space of said chamber formoving the crop received therein through said heated air during thedrying operation, said first conveying means including an endlessconveyor disposed in the bottom part of said chamber;

a second conveying means located in said first space of said chamber,said second conveying means adapted to convey crop fed thereto to saidopening for passing crop from said first space to said second space;

a third conveying means comprising a rotary tined member and a secondinternal opening in said chamber between said first and said secondspaces through which said rotary tined member moves crop from said firstconveying means in said second space to said second conveying means,said blower means producing a flow of heated air from said second spaceinto said first space through said second opening whereby said rotarytined member cooperating with said first conveying means feeds crop inthe direction of the air flow from said blower through said secondopening to said second conveying means and the crop may be continuouslycirculated through heated air within said chamber by said threeconveying means during the drying operation.

2. A device as claimed in claim 1, wherein the said rotary tined memberis disposed near one end of said endless conveyor.

3. A device as claimed in claim 1, wherein said rotary tined member isafforded by a rotary drum which is provided with resilient tines.

4. A device as claimed in claim 1, wherein the said endless conveyor andsaid rotary tined member extend throughout substantially the whole ofthe width of the said chamber.

5. A device as claimed in claim 1, wherein said endless conveyor isinclined relative to the horizontal.

6. A device as claimed in claim 1, wherein said second conveying meanscomprises a feeding channel in said first space which discharges cropinto the upper part of said chamber through said first mentionedopening.

7. A device as claimed in claim 6, wherein the said rotary member isarranged adjacent said second opening, said second openinginterconnecting said second space of said chamber and the lower aspectof said feeding channel.

8. A device as claimed in claim 7, wherein the said second conveyingmeans comprises crop-engaging tines which are arranged in said feedingchannel, said feeding channel including a lower curved portion directlycommunicating with an inlet opening of the device, said lower curvedportion connecting said inlet opening to a substantially straightportion of said feeding channel that extends upwardly and rearwardlyaway from said inlet opening.

9. A device as claimed in claim 8, wherein said second opening is formedin a wall of the feeding channel at or near the junction between saidlower curved and straight portions thereof, said second opening beingproximate the lowermost aspect of said feeding conveyor and alsoproximate one end of said endless conveyor located in said secondchamber.

10. A device as claimed in claim 8, wherein a wall included in saidstraight portion of said feeding channel lies between said feedingchannel and said second chamber, said wall having a plurality ofopenings through which drying air including other gases in said secondchamber are receivable in said feeding channel.

11. A device as claimed in claim 8, comprising feed ing members, atleast one crank shaft, and crank pins, wherein said second conveyingmeans includes a plurality of said feeding members connected side byside to said crank pins of said crank shaft, said feeding members havingresilient tine members, the feeding members having at their lowermostends curved portions which carry radial tines that extend substantiallyradially with respect to the center of curvature of said portions, saidradial tines being arranged to extend into the lower curved portions ofsaid feeding channel which directly communicates with said inletopening.

12. A device as claimed in claim 1, wherein the said endless conveyor isafforded by at least two chains transversely interconnected at spacedintervals by crop-engaging means.

13. A device as claimed in claim 1, wherein said blower means isselectively adapted to supply drying air to said drying chamber or toconvey dried crop from said chamber.

14. A device as claimed in claim 13, wherein the said blower meanscommunicates with an outlet channel extending horizontally andperpendicular to the longitudinal axis of said chamber.

15. A device as claimed in claim 13, wherein a flap is movably arrangedbetween a position in which air is supplied to said chamber for dryingpurposes and a position in which the supplied air generated by saidblower may be entrained into unloading means.

16. A device as claimed in claim 1, wherein said blower means and saidheating mechanism are arranged at one end of the device relativelyopposite to said inlet opening for receiving crop therein to be dried.

17. A device as claimed in claim 1 including a burner in said heatingmechanism rated at between 20,000 and 100,000 kcal. per hour.

18. A device as claimed in claim 1, wherein the roof of said dryingchamber is composed at least in part of material adapted to be permeatedb solar heat.

. A device as claimed in claim 8, wherein the said material is atransparent synthetic plastic material.

20. A device as claimed in claim 1, wherein at least part of each sidewall of said drying chamber is composed of material adapted to bepermeated by solar heat.

21. A device as claimed in claim 1 which includes means for deflectingthe tines of said rotary tined member to prevent said tines fromengaging said second conveying means.

22. A device as claimed in claim 1 wherein said third conveying means islocated at least in part in said second opening which includes means forretaining said tines of said rotary tined member in an upright portionin said second opening whereby when said second conveyor is stopped saidupright tines substantially prevent the passage of crop through saidsecond opening.

1. A device for drying crop including cut grass or the like whichcomprises: a drying chamber which has a first space and second spacewhich includes an internal opening for the passage of crop from saidfirst space to said second space; drying means associated with saidsecond space of said chamber, said drying means including a heatingmechanism for producing heated air in said chamber and a blower meansfor introducing air into said second space; a first conveying meansmounted in said second space of said chamber for moving the cropreceived therein through said heated air during the drying operation,said first conveying means including an endless conveyor disposed in thebottom part of said chamber; a second conveying means located in saidfirst space of said chamber, said second conveying means adapted toconvey crop fed thereto to said opening for passing crop from said firstspace to said second space; a third conveying means comprising a rotarytined member and a second internal opening in said chamber between saidfirst and said second spaces through which said rotary tined membermoves crop from said first conveying means in said second space to saidsecond conveying means, said blower means producing a flow of heated airfrom said second space into said first space through said second openingwhereby said rotary tined member cooperating with said first conveyingmeans feeds crop in the direction of the air flow from said blowerthrough said second opening to said second conveying means and the cropmay be continuously circulated through heated air within said chamber bysaid three conveying means during the drying operation.
 2. A device asclaimed in claim 1, wherein the said rotary tined member is disposednear one end of said endless conveyor.
 3. A device as claimed in claim1, wherein said rotary tined member is afforded by a rotary drum whichis provided with resilient tines.
 4. A device as claimed in claim 1,wherein the said endless conveyor and said rotary tined member extendthroughout substantially the whole of the width of the said chamber. 5.A device as claimed in claim 1, wherein said endless conveyor isinclined relative to the horizontal.
 6. A device as claimed in claim 1,wherein said second conveying means comprises a feeding channel in saidfirst space which discharges crop into the upper part of said chamberthrough said first mentioned opening.
 7. A device as claimed in claim 6,wherein the said rotary member is arranged adjacent said second opening,said second opening interconnecting said second space of said chamberand the lower aspect of said feeding channel.
 8. A device as claimed inclaim 7, wherein the said second conveying means comprises crop-engagingtines which are arranged in said feeding channel, said feeding channelincluding a lower curved portion directly communicating with an inletopening of the device, said lower curved portion connecting said inletopening to a substantially straight portion of said feeding channel thatextends upwardly and rearwardly away from said inlet opening.
 9. Adevice as claimed in claim 8, wherein said second opening is formed in awall of the feeding channel at or near the junction between said lowercurved and straight portions thereof, said second opening beingproximate the lowermost aspect of said feeding conveyor and alsoproximate one end of said endless conveyor located in said secondchamber.
 10. A device as claimed in claim 8, wherein a wall included insaid straight portion of said feeding channel lies between said feedingchannel and said second chamber, said wall having a plurality ofopenings through which drying air including other gases in said secondchamber are receivable in said feeding channel.
 11. A device as claimedin claim 8, comprising feeding members, at least one crank shaft, andcrank pins, wherein said second conveying means includes a plurality ofsaid feeding members connected side by side to said crank pins of saidcrank shaft, said feeding members having resilient tine members, thefeeding members having at their lowermost ends curved portions whichcarry radial tines that extend substantially radially with respect tothe center of curvature of said portions, said radial tines beingarranged to extend into the lower curved portions of said feedingchannel which directly communicates with said inlet opening.
 12. Adevice as claimed in claim 1, wherein the said endless conveyor isafforded by at least two chains transversely interconnected at spacedintervals by crop-engaging means.
 13. A device as claimed in claim 1,wherein said blower means is selectively adapted to supply drying air tosaid drying chamber or to convey dried crop from said chamber.
 14. Adevice as claimed in claim 13, wherein the said blower meanscommunicates with an outlet channel extending horizontally andperpendicular to the longitudinal axis of said chamber.
 15. A device asclaimed in claim 13, wherein a flap is movably arranged between aposition in which air is supplied to said chamber for drying purposesand a position in which the supplied air generated by said blower may beentrained into unloading means.
 16. A device as claimed in claim 1,wherein said blower means and said heating mechanism are arranged at oneend of the device relatively opposite to said inlet opening forreceiving crop therein to be dried.
 17. A device as claimed in claim 1including a burner in said heating mechanism rated at between 20,000 and100,000 kcal. per hour.
 18. A device as claimed in claim 1, wherein theroof of said drying chamber is composed at least in part of materialadapted to be permeated by solar heat.
 19. A device as claimed in claim18, wherein the said material is a transparent synthetic plasticmaterial.
 20. A device as claimed in claim 1, wherein at least part ofeach side wall of said drying chamber is composed of material adapted tobe permeated by solar heat.
 21. A device as claimed in claim 1 whichincludes means for deflecting the tines of said rotary tined member toprevent said tines from engaging said second conveying means.
 22. Adevice as claimed in claim 1 wherein said third conveying means islocated at least in part in said second opening which includes means forretaining said tines of said rotary tined member in an upright portionin said second opening whereby when said second conveyor is stopped saidupright tines substantially prevent the passage of crop through saidsecond opening.